feat: gas manager for loadtest; add tx-gas-chart #755

tclemos · 2025-10-21T06:45:40Z

closes https://github.com/0xPolygon/devtools/issues/444

This PR adds a Gas Manager to the loadtest command and introduces a new tx-gas-chart visualization tool.

Gas Manager features:

Gas Vault: Budget-based throttling that controls transaction flow per block
Wave Patterns: Five oscillation patterns (flat, sine, square, triangle, sawtooth) to simulate varying network conditions
Gas Pricing Strategies: Three strategies (estimated, fixed, dynamic) for flexible gas price simulation

New tx-gas-chart command:

Generates visual PNG charts analyzing transaction gas prices and limits across block ranges
Displays four metrics: transaction gas prices, transaction gas limits, block gas limits, and block gas used
Supports highlighting transactions from/to specific addresses
Configurable scale (logarithmic or linear) for gas price visualization
Useful for analyzing gas patterns during load tests or investigating network behavior

Use cases:

Simulate realistic network congestion patterns during load tests
Run infinite load tests with controlled gas consumption
Visualize gas price and usage patterns across blocks
Stress test networks with oscillating transaction loads

…urve

Copilot

Pull Request Overview

This PR introduces a gas limiting mechanism for the loadtest command to control transaction flow through configurable gas budgets and oscillation curves. The feature aims to enable running loadtests indefinitely while managing gas consumption patterns.

Key changes:

Adds a new gaslimiter package implementing a gas vault system and oscillating gas provider
Refactors loadtest functions to return transaction objects instead of transaction hashes
Implements gas budget tracking with configurable oscillation curves for dynamic gas limit control

Reviewed Changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated 9 comments.

Show a summary per file

File	Description
cmd/loadtest/gaslimiter/curve.go	Defines base curve interface and configuration for gas oscillation patterns
cmd/loadtest/gaslimiter/curve_sine.go	Implements sinusoidal curve for oscillating gas budgets
cmd/loadtest/gaslimiter/curve_sine_test.go	Tests sine curve implementation with expected values
cmd/loadtest/gaslimiter/gas_vault.go	Implements thread-safe gas budget storage with spend/wait mechanism
cmd/loadtest/gaslimiter/gas_provider.go	Base gas provider that watches for new block headers
cmd/loadtest/gaslimiter/gas_provider_oscillating.go	Oscillating gas provider that adds gas based on curve values per block
cmd/loadtest/gaslimiter/README.md	Documentation for gas limiter components and workflow
cmd/loadtest/loadtest.go	Integrates gas limiter into main loadtest loop and refactors transaction handling
cmd/loadtest/uniswapv3.go	Updates UniswapV3 loadtest to return transaction object instead of hash

_{Tip: Customize your code reviews with copilot-instructions.md. Create the file or learn how to get started.}

cmd/loadtest/gasmanager/gas_vault.go

cmd/loadtest/gasmanager/gas_provider.go

cmd/loadtest/gaslimiter/curve_sine.go

cmd/loadtest/loadtest.go

Fix panic caused by signing a nil transaction in loadTestContractCall. The transaction was being built and assigned to `tx`, but the code was incorrectly trying to sign `rtx` which was declared but never assigned. This caused a segmentation fault when using the `contract-call` mode: panic: runtime error: invalid memory address or nil pointer dereference at cmd/loadtest/loadtest.go:1987 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude <noreply@anthropic.com>

…de gas

cmd/txgaschart/cmd.go

util/util.go

Copilot

Pull request overview

Copilot reviewed 33 out of 39 changed files in this pull request and generated 11 comments.

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

Copilot · 2025-12-29T20:18:04Z

util/util.go

+func GetSenderFromTx(ctx context.Context, tx rpctypes.PolyTransaction) (common.Address, error) {
+	// Get transaction type
+	txType := tx.Type()
+
+	// For non-standard transaction types, we assume the sender is already set
+	if txType > 2 {
+		return tx.From(), nil
+	}
+
+	// Get transaction fields
+	chainID := tx.ChainID()
+	nonce := tx.Nonce()
+	value := tx.Value()
+	gas := tx.Gas()
+	to := tx.To()
+	data := tx.Data()
+	v := tx.V()
+	r := tx.R()
+	s := tx.S()
+
+	// Calculate the signing hash based on transaction type
+	var sigHash []byte
+	var err error
+
+	switch txType {
+	case 0: // Legacy transaction
+		sigHash, err = calculateLegacySigningHash(chainID, nonce, tx.GasPrice(), gas, to, value, data)
+	case 1: // EIP-2930 (Access List)
+		// For now, we can try with empty access list
+		// If you need full support, you'll need to add AccessList to PolyTransaction interface
+		sigHash, err = calculateEIP2930SigningHash(chainID, nonce, tx.GasPrice(), gas, to, value, data, []interface{}{})
+	case 2: // EIP-1559
+		maxPriorityFee := new(big.Int).SetUint64(tx.MaxPriorityFeePerGas())
+		maxFee := new(big.Int).SetUint64(tx.MaxFeePerGas())
+		sigHash, err = calculateEIP1559SigningHash(chainID, nonce, maxPriorityFee, maxFee, gas, to, value, data)
+	default:
+		return common.Address{}, fmt.Errorf("unsupported transaction type: %d (0x%x)", txType, txType)
+	}
+
+	if err != nil {
+		return common.Address{}, fmt.Errorf("failed to calculate signing hash: %w", err)
+	}
+
+	// Normalize v value for recovery
+	var recoveryID byte
+	if txType == 0 {
+		// Legacy transaction with EIP-155
+		if chainID > 0 {
+			// EIP-155: v = chainId * 2 + 35 + {0,1}
+			// Extract recovery id: recoveryID = v - (chainId * 2 + 35)
+			vBig := new(big.Int).Set(v)
+			vBig.Sub(vBig, big.NewInt(35))
+			vBig.Sub(vBig, new(big.Int).Mul(new(big.Int).SetUint64(chainID), big.NewInt(2)))
+			recoveryID = byte(vBig.Uint64())
+		} else {
+			// Pre-EIP-155: v is 27 or 28
+			recoveryID = byte(v.Uint64() - 27)
+		}
+	} else {
+		// EIP-2930 and EIP-1559: v is 0 or 1 (or 27/28)
+		vVal := v.Uint64()
+		if vVal >= 27 {
+			recoveryID = byte(vVal - 27)
+		} else {
+			recoveryID = byte(vVal)
+		}
+	}
+
+	// Validate recoveryID
+	if recoveryID > 1 {
+		return common.Address{}, fmt.Errorf("invalid recovery id: %d (v=%s, chainID=%d, type=%d)", recoveryID, v.String(), chainID, txType)
+	}
+
+	// Build signature in the [R || S || V] format (65 bytes)
+	sig := make([]byte, 65)
+	// Use FillBytes to ensure proper padding with leading zeros
+	r.FillBytes(sig[0:32])
+	s.FillBytes(sig[32:64])
+	sig[64] = recoveryID
+
+	// Recover public key from signature using go-ethereum's crypto package
+	pubKey, err := crypto.Ecrecover(sigHash, sig)
+	if err != nil {
+		return common.Address{}, fmt.Errorf("failed to recover public key: %w", err)
+	}
+
+	// Derive address from public key
+	// The public key returned by Ecrecover is 65 bytes: [0x04 || X || Y]
+	// We hash the X and Y coordinates (skip first byte) and take last 20 bytes
+	hash := crypto.Keccak256(pubKey[1:])
+	address := common.BytesToAddress(hash[12:])
+
+	return address, nil
+}


The function lacks test coverage for the transaction sender recovery logic. Given the complexity of handling multiple transaction types (Legacy, EIP-2930, EIP-1559) and the critical nature of signature recovery, comprehensive tests should be added to verify correct sender address recovery for all transaction types.

Copilot · 2025-12-29T20:18:04Z

cmd/txgaschart/usage.md

+  ```bash
+  $ polycli tx-gas-chart --rpc-url http://localhost:8545
+
+  This will create a file named tx_gasprice_chart.png in the current directory.


The markdown formatting is broken. The code block starting at line 9 is not properly closed. Line 11 should have triple backticks to close the code block before continuing with the next section heading. The same issue appears to occur throughout this file where bash code examples are not properly formatted.

Copilot · 2025-12-29T20:18:05Z

cmd/loadtest/gasmanager/README.md

+```bash
+# Configure the oscillation wave pattern
+--gas-manager-oscillation-wave string   # Wave type: flat, sine, square, triangle, sawtooth (default: "flat")
+--gas-manager-target uint64             # Target gas limit baseline (default: 30000000)
+--gas-manager-period uint64             # Period in blocks for wave oscillation (default: 1)
+--gas-manager-amplitude uint64          # Amplitude of oscillation (default: 0)
+
+Gas Price Control (Pricing Strategy)
+
+# Select and configure pricing strategy
+--gas-manager-price-strategy string                # Strategy: estimated, fixed, dynamic (default: "estimated")
+--gas-manager-fixed-gas-price-wei uint64           # Fixed price in wei (default: 300000000)
+--gas-manager-dynamic-gas-prices-wei string        # Comma-separated prices for dynamic strategy
+                                                   # Use 0 for network-suggested price
+                                                   # (default: "0,1000000,0,10000000,0,100000000")
+--gas-manager-dynamic-gas-prices-variation float64 # Variation ±percentage for dynamic prices (default: 0.3)
+
+Examples


The markdown code block is not properly closed. Line 86 ends the bash code block but line 87 "Gas Price Control (Pricing Strategy)" should be a markdown heading (starting with ###) instead of plain text. The subsequent bash code block starting at line 89 is also not properly opened with triple backticks.

Copilot · 2025-12-29T20:18:05Z

cmd/txgaschart/cmd.go

+	}
+	wg.Wait()
+
+	blocks.avgBlockGasUsed = big.NewInt(0).Div(totalGasUsed, big.NewInt(int64(len(blocks.blocks)))).Uint64()


Using uint64 value for division with big.Int can cause precision loss. When dividing totalGasUsed (a *big.Int) by the number of blocks (converted to int64), you should ensure that the conversion doesn't lose data. Consider checking if len(blocks.blocks) can safely be converted to int64, or use big.Int arithmetic throughout to avoid potential overflow issues.

Suggested change

blocks.avgBlockGasUsed = big.NewInt(0).Div(totalGasUsed, big.NewInt(int64(len(blocks.blocks)))).Uint64()

if len(blocks.blocks) > 0 {

divisor := new(big.Int).SetUint64(uint64(len(blocks.blocks)))

blocks.avgBlockGasUsed = new(big.Int).Div(totalGasUsed, divisor).Uint64()

}

Copilot · 2025-12-29T20:18:05Z

util/util.go

+
+	// Validate recoveryID
+	if recoveryID > 1 {
+		return common.Address{}, fmt.Errorf("invalid recovery id: %d (v=%s, chainID=%d, type=%d)", recoveryID, v.String(), chainID, txType)


The error messages include chainID in the format string but only when the transaction type is legacy with EIP-155. For other transaction types (EIP-2930, EIP-1559), chainID is still included in the error message even though it may not be relevant to the specific recovery failure. Consider making the error message more specific to the transaction type being processed.

Copilot · 2025-12-29T20:18:06Z

cmd/loadtest/gasmanager/gas_vault.go

+package gasmanager
+
+import (
+	"math"
+	"sync"
+	"time"
+
+	"github.com/rs/zerolog/log"
+)
+
+// GasVault manages a budget of gas that can be added to and spent from.
+type GasVault struct {
+	mu                 *sync.Mutex
+	gasBudgetAvailable uint64
+}
+
+// NewGasVault creates a new GasVault instance.
+func NewGasVault() *GasVault {
+	return &GasVault{
+		mu:                 &sync.Mutex{},
+		gasBudgetAvailable: 0,
+	}
+}
+
+// AddGas adds the specified amount of gas to the vault's available budget.
+func (o *GasVault) AddGas(gas uint64) {
+	o.mu.Lock()
+	defer o.mu.Unlock()
+	if o.gasBudgetAvailable+gas < o.gasBudgetAvailable {
+		o.gasBudgetAvailable = math.MaxUint64
+		log.Trace().Uint64("available_budget_after", o.gasBudgetAvailable).Msg("gas budget in vault capped to max uint64")
+	} else {
+		o.gasBudgetAvailable += gas
+		log.Trace().Uint64("available_budget_after", o.gasBudgetAvailable).Msg("new gas budget available in vault")
+	}
+}
+
+// SpendOrWaitAvailableBudget attempts to spend the specified amount of gas from the vault's available budget.
+func (o *GasVault) SpendOrWaitAvailableBudget(gas uint64) {
+	const intervalToCheckBudgetAvailability = 100 * time.Millisecond
+	for {
+		if spent := o.trySpendBudget(gas); spent {
+			break
+		}
+		time.Sleep(intervalToCheckBudgetAvailability)
+	}
+}
+
+// trySpendBudget tries to spend the specified amount of gas from the vault's available budget.
+// It returns true if the gas was successfully spent, or false if there was insufficient budget.
+func (o *GasVault) trySpendBudget(gas uint64) bool {
+	o.mu.Lock()
+	defer o.mu.Unlock()
+	if gas <= o.gasBudgetAvailable {
+		o.gasBudgetAvailable -= gas
+		return true
+	}
+	return false
+}
+
+// GetAvailableBudget returns the current available gas budget in the vault.
+func (o *GasVault) GetAvailableBudget() uint64 {
+	o.mu.Lock()
+	defer o.mu.Unlock()
+	return o.gasBudgetAvailable
+}


The gas manager components (GasVault, GasProvider, GasPricer, and pricing strategies) lack test coverage. While wave patterns are tested, the core functionality of gas budget management, provider behavior, and pricing strategies should also have comprehensive unit tests to ensure correct behavior under various conditions.

Copilot · 2025-12-29T20:18:06Z

cmd/loadtest/gasmanager/README.md

+Visualization with tx-gas-chart
+
+You can visualize the gas patterns generated by your loadtest using the tx-gas-chart command:
+
+# Run loadtest with sine wave pattern
+polycli loadtest \
+  --rpc-url http://localhost:8545 \
+  --gas-manager-oscillation-wave sine \
+  --gas-manager-period 100 \
+  --gas-manager-amplitude 10000000 \
+  --target-address 0xYourAddress
+
+# Generate chart to visualize results
+polycli tx-gas-chart \
+  --rpc-url http://localhost:8545 \
+  --target-address 0xYourAddress \
+  --output sine_wave_result.png
+
+How It Works


The markdown formatting is inconsistent. "Visualization with tx-gas-chart" (line 169), "How It Works" (line 187), and other section headings should use markdown heading syntax (e.g., "## Visualization with tx-gas-chart") instead of plain text. Additionally, the bash code examples starting at line 173 are not properly enclosed in triple backtick code blocks.

Copilot · 2025-12-29T20:18:06Z

cmd/loadtest/gasmanager/strategy_dynamic_gas.go

+
+	variationMin := float64(1) - s.config.Variation
+	variationMax := float64(1) + s.config.Variation
+	factor := variationMin + rand.Float64()*variationMax


The factor calculation is incorrect. When calculating random variation, you're computing variationMin + rand.Float64() * variationMax, which adds the maximum variation to the minimum. This should be multiplying by the range, not the max. The correct formula should be: factor := variationMin + rand.Float64() * (variationMax - variationMin). Currently, with a variation of 0.3, you'll get factors ranging from 0.7 to approximately 1.7-2.0 instead of the intended 0.7 to 1.3.

Suggested change

factor := variationMin + rand.Float64()*variationMax

factor := variationMin + rand.Float64()*(variationMax-variationMin)

Copilot · 2025-12-29T20:18:06Z

cmd/loadtest/loadtest.go

+		// loadTestModeERC721,
+		// loadTestModeDeploy,
+		// loadTestModeIncrement,
+		// loadTestModeStore,


The random mode selection has been commented out, leaving only loadTestModeERC20 and loadTestModeTransaction active. If this is intentional for the gas manager feature, it should be explained in a comment. If this is temporary debugging code, it should be reverted before merging.

Copilot · 2025-12-29T20:18:07Z

cmd/txgaschart/chart.go

+			// Ensure gasPrice is >= 1 for logarithmic scale
+			gasPrice := t.gasPrice
+			if gasPrice <= 0 {
+				gasPrice = 1
+			}
+
+			// Use the local gasPrice variable (protected) in all appends


The conditional check for negative or zero gas price values is performed, but the modified gasPrice variable is reassigned after the check. This means the protection is applied, but then you're working with the protected value. However, there's a subtle issue: when t.gasPrice is 0 and you set gasPrice = 1 for protection, you then append gasPrice (the protected value) to the txGroups, which is correct. But the log scale protection should be mentioned in a comment to explain why gas prices can be modified from their original values.

Suggested change

// Ensure gasPrice is >= 1 for logarithmic scale

gasPrice := t.gasPrice

if gasPrice <= 0 {

gasPrice = 1

}

// Use the local gasPrice variable (protected) in all appends

// For plotting on a logarithmic Y scale we must avoid zero/negative values.

// Clamp gasPrice to at least 1 for visualization purposes; this means the

// plotted gas price may differ from the original t.gasPrice when it is <= 0.

gasPrice := t.gasPrice

if gasPrice <= 0 {

gasPrice = 1

}

// Always use the protected gasPrice value for all plotted points.

tclemos added 2 commits October 18, 2025 16:09

loadtest: WIP first version of a gas limiter based on a oscillation c…

6df5694

…urve

add traces; add gas limiter readme; fix infinte loadtest loop;

d1b2b61

tclemos requested a review from Copilot October 21, 2025 06:45

tclemos self-assigned this Oct 21, 2025

Copilot AI reviewed Oct 21, 2025

View reviewed changes

add gas pricer; add flags to gasmanager; rename to gasmanager package

cb8eec5

minhd-vu changed the title ~~[WIP]feat: gas limiter for loadtest~~ [WIP] feat: gas limiter for loadtest Oct 21, 2025

tclemos added 10 commits October 24, 2025 10:21

add tx-gas-chart command; adjusts to gas manager

df895e6

refactoring loadtest gas price manager waves and tx-gas-chart;

6913ade

refactoring loadtest gas price manager waves and tx-gas-chart;

efd46ad

gas manager and tx-gas-chart refactoring and docs;

14bde21

adds usage documentation for tx-gas-chart

a54d7a5

improves documentation for gasmanager package

a2e8784

Merge branch 'main' into thiago/loadtest-gas-oscillation

a6306b5

refactoring

281d293

make gen-doc

c84d18a

Merge branch 'main' into thiago/loadtest-gas-oscillation

045b61b

tclemos marked this pull request as ready for review November 5, 2025 13:46

tclemos requested a review from praetoriansentry November 5, 2025 13:47

tclemos changed the title ~~[WIP] feat: gas limiter for loadtest~~ feat: gas limiter for loadtest; add tx-gas-chart Nov 5, 2025

tclemos changed the title ~~feat: gas limiter for loadtest; add tx-gas-chart~~ feat: gas manager for loadtest; add tx-gas-chart Nov 5, 2025

tclemos and others added 7 commits November 5, 2025 11:36

small doc formating

8be800a

loadtest: remove infinite; gas provider wait first new block to provi…

e1143f6

…de gas

make gen-doc

bfa4469

Merge branch 'main' into thiago/loadtest-gas-oscillation

cd1dc88

WIP

9ec1165

Merge branch 'main' into thiago/loadtest-gas-oscillation

9a7c411

leovct reviewed Dec 1, 2025

View reviewed changes

cmd/txgaschart/cmd.go Outdated Show resolved Hide resolved

tx-gas-chart: make it compatible with op-stack deposit txs

cf4b2fd

github-advanced-security bot found potential problems Dec 5, 2025

View reviewed changes

cmd/txgaschart/cmd.go Fixed Show fixed Hide fixed

util/util.go Fixed Show fixed Hide fixed

util/util.go Fixed Show fixed Hide fixed

util/util.go Fixed Show fixed Hide fixed

tclemos added 5 commits December 9, 2025 08:28

chart header fix

8487df0

Merge branch 'main' into thiago/loadtest-gas-oscillation

d4e585b

fix merge conflicts

3bb36dd

tx-gas-chart: allow start block to be zero

b31daed

fix codeql issues

a71900b

tclemos requested a review from Copilot December 29, 2025 20:10

Copilot started reviewing on behalf of tclemos December 29, 2025 20:10 View session

Copilot AI reviewed Dec 29, 2025

View reviewed changes

add unit tests to TestGetSenderFromTx

2682887

-	blocks.avgBlockGasUsed = big.NewInt(0).Div(totalGasUsed, big.NewInt(int64(len(blocks.blocks)))).Uint64()
+	if len(blocks.blocks) > 0 {
+		divisor := new(big.Int).SetUint64(uint64(len(blocks.blocks)))
+		blocks.avgBlockGasUsed = new(big.Int).Div(totalGasUsed, divisor).Uint64()
+	}

	factor := variationMin + rand.Float64()*variationMax
	factor := variationMin + rand.Float64()*(variationMax-variationMin)

feat: gas manager for loadtest; add tx-gas-chart #755

Are you sure you want to change the base?

feat: gas manager for loadtest; add tx-gas-chart #755

Uh oh!

Conversation

tclemos commented Oct 21, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull Request Overview

Reviewed Changes

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Uh oh!

Copilot AI Dec 29, 2025

Choose a reason for hiding this comment

Uh oh!

Copilot AI Dec 29, 2025

Choose a reason for hiding this comment

Uh oh!

Copilot AI Dec 29, 2025

Choose a reason for hiding this comment

Uh oh!

Copilot AI Dec 29, 2025

Choose a reason for hiding this comment

Uh oh!

Copilot AI Dec 29, 2025

Choose a reason for hiding this comment

Uh oh!

Copilot AI Dec 29, 2025

Choose a reason for hiding this comment

Uh oh!

Copilot AI Dec 29, 2025

Choose a reason for hiding this comment

Uh oh!

Copilot AI Dec 29, 2025

Choose a reason for hiding this comment

Uh oh!

Copilot AI Dec 29, 2025

Choose a reason for hiding this comment

Uh oh!

Copilot AI Dec 29, 2025

Choose a reason for hiding this comment

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

4 participants

tclemos commented Oct 21, 2025 •

edited

Loading